I would like to replace a regular door with a pocket slidiing door.?

Do a barn door instead. The pocket door was a nightmare. The door rolls on a track, and depending on how and where you put your hand to close it. It would come off the track. Getting back on the track wasn’t easy, as the hanging hardware was inside the wall.

https://www.popularmechanics.com/home/interior-projects/how-to/a1280/install-a-pocket-door/

It came with the house I purchased, it was on top of the basement stairs, in a narrow hall. No room for a swinging door. It did make sense in that situation, I just left the room door less..the laundry and the cat boxes were in that room.

It came with the house I bought, and there were 2 of those doors. 1 at the top of the steps to the lower level, the other for the laundry room. I kept a lever near by to get them lifted up to re hang them, and a clothes hanger that I straighten out to use the hook part to catch the doors hanger.

the hallway was narrow, a regular door would not have the swing room to open fully.

It came with the house.....

it came with the house I purchased, 2 pocket doors..1 at the top of the lower level doorway the other for the laundry room. the hallway was narrow, a swinging door would not have room to open fully. the lower level had been converted to an apartment for the previous owners grandson who was taking classes at the towns university.

the doors came with the house - i refer to it as house no.2, 1 of the sliders were over the stairs to the lower level, the other was a door to the laundry room, which should have been the 3rd upstairs bed room. the hallway was narrow, a full sized door would have hit the the opposing wall. i kept a straightened out cloths hanger, used the hook part to retrieve rolling hanger parts to remount the doors. major P.I.A. the lower level looked out into the back yard where my veggie garden was.

that house was split into 2 different living areas, one for the elderly grandparents, and a college aged grandson- he got the galley kitchen in the lower level, the grands lived up stairs. oddly enough...a father daughter combo bought that house from me. he up stairs, she got the down stairs. that's the house that sold first day on the market.

the doors came with house no.2, the hallway was narrow no room to swing a door with out it banging the walls. the door to the lower level, the door to the laundry, both were pocket doors. I moved out of that house in 2014. never regretted it.